Private clinics in Sydney?

I have some sickness and instead of sending me for further checks ( blood test) to find the root casue, doctors are just precribing me different antibiotics in the health care centre which are not helping at all. They are very kind bur I don't think they even listen carefully when I'm describing the symptoms. Does anyone know about any private clinics around Sydney where a throurough health check can be made to define the right treatment? thanks